a) Field of the Invention
The present invention relates generally to the woodworking art, and more particularly to the making of finished wooden articles, such as cabinets (either built in or free standing), bookshelves, magazine racks, furniture, etc. More particularly, the present invention relates to the manner in which the exposed heads of the wood screws are covered in making the finished article.
b) Background Art
A variety of people are involved in the woodworking industry. There is the professional woodworker who makes quality items such as cabinets, desks or bookcases, or even larger projects such as building entire interior of a kitchen in a home. Also, there are those who have woodworking for a hobby, with varying degrees of skill. Then there are the people who do not actually work in the woodworking art, but who will purchase various items, such as desks, chairs, bookshelves, etc., the components of which are premade, but not assembled. Then this person has the task of joining the various pieces together by placing the pieces in the appropriate preassembled position, inserting the screws one at a time, and using a screwdriver to screw these in to hold the pieces in place.
After the screws are in place, all of these people (the professional woodworker, the amateur woodworker, and the person simply assembling a premade article) have a common problem, and this is how to cover the exposed heads of the screws. Quite commonly, these screws are countersink screws where the non-exposed surface of the screw head has a frusto conical shape, and the hole is drilled as a countersunk hole, where the outer portion of the hole has a corresponding frusto conical shape. Thus, when the screw is inserted, the exposed face of the screw head is flush with (or nearly flush with) the adjacent surface of the wood piece into which the screw is inserted. For many decades, the commonplace method of covering the exposed screw head is to place a cap over the exposed screw head, and push the cap into retaining engagement with the screw head. The cap is configured so that it has a dome shaped cap portion and a center stub or probe which matches the configuration of the Philips head recess in the exposed surface of the screw. When the cap is pressed against the screw head, the probe comes into retaining engagement with the screw head.
It sometimes happens that the countersink recess of the premade screw hole is a slight amount out of tolerance, in that it has been drilled too deeply. In this instance, when the screw is inserted and tightened up in firm engagement, the exposed surface of the screw head is a short distance below the surrounding surface of the wood piece into which it is inserted. The result of this is that the probe of the cover cap does not properly engage the Philips head recess and the screw head. Then the person needs to either press or hammer the cover cap further into the screw hole, so that the dome shaped cover cap flattens out and the probe does come into proper engagement. This particular prior art process will be described more fully later in the text of this application with reference to FIGS. 1 through 8.
One of the undesirable results of this is that with some frequency the cover caps become dislodged (probably because they were never secured properly in the first place). Also, there are inconveniences in the application of the caps. Yet, this particular type of cover cap and the method of installing the same has remained as the state of the art for many decades, and to the best knowledge of the applicant, no improved method has been adopted in the woodworking industry. A search of the patent literature has disclosed a number of cover devices for a fastener the earliest patent disclosed in this search issued in 1882 and the most recent issued in 1995. These are as follows.
U.S. Pat. No. 5,419,666 (Best) shows a protective cover assembly to provide a waterproof cover over a fastener, this being used, for example, in roof structures. There is a dome shaped rigid cover which fits over the head of the screw. Then a flexible waterproof circular pad having a diameter greater than the dome shaped cover overlies the cover with the perimeter of the pad adhering to the support surface.
U.S. Pat. No. 4,701,089 (Nettel) provides a "quick release cover" which has at its center downwardly extending fingers which grasp the slot in the closure member or screw.
U.S. Pat No. 4,630,168 (Hunt) shows a "lightning protection fastener" used in aircraft. There is a metallic fastener having a dielectric cap to fill a gap between the fastener head and the counterbored surface on which the fastener is installed. It provides a continuous flush surface for receiving a crack-free coat of paint.
U.S. Pat. No 4,601,624 (Hill) shows a screw head cover that is held in place by a retaining element that is itself held by the screw.
U.S. Pat. No. 3,885,492 (Gutshall) shows a fastener for attaching sheet metal paneling to the outside wall of a building. There is a resilient screw head cover that is flexible enough to allow a tool to enter the fastener's head.
U.S. Pat. No. 3,122,051 (Greene) shows a decorative screw cover which has a snap connection to a washer which is placed beneath the screw head.
U.S. Pat. No. 2,363,665 (George) shows a cap to cover the head of a screw. The cover has legs which fit snugly in the countersink Philips slot in the screw head.
U.S. Pat. No. 915,058 (Bowen) issued in 1909 and shows a cover for the head of a screw which has a connecting member fitting in the slot in the head of the screw.
U.S. Pat. No. 264,776 (Sharp) issued in 1882, and this shows a hollow plug which fits into the upper portion of a countersink slot that is above the head of the screw. This permits expansion of the screw without displacement of the plug.
Also, the applicant is aware of a commercial product which is a planar circular cover having a diameter moderately larger than the screw hole which is to be covered. There is an adhesive surface by which the material can be placed over the screw hold and bonded in place. This is made of a quite flexible material. To the best knowledge of the applicant, this has not obtained a wide commercial success. The characteristics of this particular cover member are discussed later in the text of this application in connection with tests that were conducted to determine the desired characteristics of the cover member of the present invention.